However,
it is worthwhile to compare the magnitude of our estimates
from the matching technique and from switching regression
with those using OLS. In general, Table 7 provides evidence
that OLS results in overestimates of the returns. The reason
for the difference is that the matching model and switching
regression allow for the sample to be drawn from self-selected
firms that are more likely to benefit from IT outsourcing while
OLS does not.